Characteristics of cognitive function in patients after traumatic brain injury assessed by visual and auditory event-related potentials.

OBJECTIVE: Using auditory and visual stimuli including facial affective stimuli, we analyzed the P300 components of event-related potentials (ERPs) in patients after traumatic brain injury (TBI) to assess their cognitive characteristics. DESIGN: Twenty TBI patients and 32 age-matched control subjects were recruited. Using conventional oddball paradigms, visual ERPs were recorded using images of crying and smiling babies as visual stimuli. Auditory ERPs were obtained using 2-kHz tones as stimuli without affective stimuli. The peak amplitude and latency for P300, and the latency for N200, were recorded. RESULTS: : In visual ERPs, the P300 amplitudes were significantly smaller in patients than in controls for the crying baby, but the amplitudes were similar between groups for the smiling baby. Controls showed smaller P300 amplitudes for the smiling baby than for the crying baby, but patients showed no difference. In patients, the P300 latency for both smiling and crying babies was longer than in the controls. Patients' auditory ERPs showed smaller P300 amplitudes but similar P300 latencies compared with controls. The N200 latency in patients was significantly longer than in controls only for the crying baby. CONCLUSIONS: Visual ERPs are a potentially useful marker for evaluating cognitive dysfunction in patients after TBI.

Full-scale granular sludge Anammox process.

The start-up of the first full scale Anammox reactor is complete. The reactor shows stable operation, even at loading rates of 10 kg N/m3.d. This performance is the result of the formation of Anammox granules, which have a high density and settling velocities exceeding 100 m/h. With this performance, the Anammox granular sludge technology has been proven on full scale.

Effect of inorganic carbon on nitrite accumulation in an aerobic granule reactor.

Pilot scale experiments were performed to evaluate the potential of nitrite type nitrification process with an airlift reactor and granular biomass. Initially, oxygen limitation was used as the main control parameter for accumulating nitrite in the effluent. After 30 d operation, the maximum nitrite conversion rate reached 2.5 kgNO2-N m(-3) d(-1), average diameter of the granule was 0.7 mm. Nitrite type reaction continued over 100 d, but nitrate formation increased after 150 d of operation. Once nitrate formation increased, oxygen limitation could not eliminate nitrite oxidising bacteria from granule. To overcome nitrate formation, laboratory scale batch experiments were conducted and it revealed a high concentration of inorganic carbon which had a significant effect on nitrite accumulation. Following this new concept, inorganic carbon was fed to the pilot scale reactor by changing pH adjustment reagent from NaOH to Na2CO3 and nitrite accumulation was recovered successfully without changing DO concentration. These results show that a high concentration of inorganic carbon is one of the control parameters for accumulating nitrite in biofilm nitrification system.

Operation of a nitrite-type airlift reactor at low DO concentration.

Laboratory scale experiments were performed to evaluate the feasibility and potential of nitrite-type nitrification process with an airlift reactor having aerobic granular biomass. Oxygen limitation was selected as the main control parameter for inhibiting the growth of nitrite oxidizer and thus achieving only nitritation. To enhance granule formation, seeding of methanogenic anaerobic granules was used to serve as an initial carrier material. After 90 days of operation at low DO concentration of less than 1.0 mg/l, the maximum nitrite conversion rate of 2.6 g NO2-N/L/d could be achieved. During the continuing year-long stable operation, the granular mass of nitritation granules increased to about 15 g VSS/L with an average granule size of 0.7 mm. Nitrate-N concentration was observed to be below 10 mg/L during the whole operational period. From the results of the experiments, it is concluded that a granule-type airlift reactor with DO control is feasible for achieving stable nitritation.

Granulation of Anammox microorganisms in up-flow reactors.

Experimental studies were performed to evaluate the feasibility of granulation of Anammox microorganisms for biomass retention in up-flow reactors. Two experimental studies, one using a 6.4-L lab-scale reactor with synthetic medium and the other using a 200-L pilot-scale reactor with half-nitrified reject water from a sludge digester were conducted. To enhance the granulation process, seed granules from a UASB reactor were added to both experimental reactors. Granulation of Anammox microorganisms was observed using both the synthetic medium and the reject water. The core of a large proportion of Anammox granules retained part of the original seed biomass. The Anammox granules had a slightly lower density than the seed granules from the UASB process, but the size and other physical properties were comparable. The successful granulation of the Anammox microorganisms led to a stable nitrogen removal performance. The maximum nitrogen removal rate of the lab-scale reactor was observed to be 2.9 kg/(m3 x d) after 173 days of operation and that of the pilot-scale reactor was 6.4 kg/(m3 x d) after 12 months of operation.

Optimal process configuration for anaerobic digestion with ozonation.

Economical source minimization of excess sludge production is an attractive option to deal with the problem of sludge disposal under strict disposal standards. In this paper long-term operational results for two different process configurations that combine oxidative ozone treatment with anaerobic sludge digestion are described. In the first configuration ozone pretreatment was combined with chemostat anaerobic digestion while in the second configuration ozone pre/post-treatments were combined with an anaerobic digester operated without solid removal. From the results of chemostat experiments, the ozone pretreatment solubilized around 19% and 37% of the solids at 0.015 and 0.05 gO3/gTS ozone dose respectively. The ozone pretreatment resulted in improved TVS reduction efficiencies and the degradation efficiencies were observed to depend on the applied ozone dose and system SRT. The TVS degradation efficiency for pre-ozonated sludge at an ozone dose of 0.05 gO3/gTS was 59% as compared to 31% for the control reactor fed with un-ozonated sludge. Test results with the second configuration indicated that overall TVS removal efficiencies for a process scheme with post-ozonation could be improved up to 85% with a minimum ozone dose of 0.045 gO3/gTVS-fed. However, since no solids (except that for sampling) were withdrawn in this configuration, the accumulated total solids in the reactors increased to 28 g/l to 30 g/l at pseudosteady state. The average specific methane recoveries were observed to be 0.36 lCH4/gTVS fed which were slightly lower than theoretically expected. Based on the experimental results, important points in the choice of process configuration are discussed.

Anaerobic digestion of excess activated sludge with ozone pretreatment.

Source minimization of excess sludge production by economical means can be considered an attractive option to deal with the problem of sludge disposal under strict disposal standards. In this paper long-term operational results for a process that combines the oxidative ozone pretreatment with anaerobic sludge digestion are described. The ozone pretreatment solubilized around 19% and 37% of the solids at 0.015 and 0.05 gO3/gTS ozone dose. The solubilization ratios during ozonation did not show any significant difference for the sludge concentrations ranging from 1.8-2.6%. The TVS concentrations after ozone treatment were observed to be about 3% lower than the feed sludge concentrations suggesting only partial mineralization during ozonation. The ozone pretreatment resulted in improved solid reduction efficiencies during anaerobic digestion leading to higher methane recovery. The TVS removal efficiencies during anaerobic digestion were observed to increase by a maximum of 35-90% depending on the applied ozone dose during ozone pretreatment. The improvement in TVS degradation efficiency at different applied ozone doses correlated well with the extent of solubilization during ozonation. Long-term data also suggested that biomass acclimation to ozonated sludge was necessary before higher degradation efficiencies could be achieved.

Circulating endothelial cells in Kawasaki disease.

Recent reports have demonstrated that circulating endothelial cells (CECs) are observed in several diseases with vascular injury. Because Kawasaki disease (KD) is one type of systemic vasculitis, we hypothesized that an increased number of CECs may be associated with the appearance of complicated coronary artery lesions (CAL). In the present study we investigated the enumeration and origin of CECs in 20 patients with KD, using an immunohistochemical method with monoclonal antibodies: clone P1H12 against ECs and clone AC133 against endothelial progenitor cells (EPCs), which were derived from the bone marrow. The mean number of CECs increased significantly (P < 0.05) from the acute through the subacute phases of KD compared with both the convalescent phase of KD and healthy children. The mean number of CECs was significantly (P < 0.05) higher in six KD patients with CAL than in 14 KD patients without CAL. The population of EPCs in the total CECs in KD was 4.4 +/- 1.2% (range 0-18%). The number of EPCs during the subacute phase was also significantly higher (P < 0.05) in KD patients with CAL than in those without CAL. Our findings indicate that the number of CECs increase in KD vasculitis and suggest that the increased numbers of CECs and EPCs may reflect the EC damage of this disease.

Characteristic profile of intestinal microflora in Kawasaki disease.

UNLABELLED: To investigate whether the ecology of the intestinal microflora may change in the acute phase of Kawasaki disease (KD), the distribution pattern was studied of common micro-organisms in feces from 20 patients with KD, 20 patients with acute febrile diseases (disease control) and 20 healthy children. KD patients had a significantly lower (p < 0.001) incidence of Lactobacillus (2/20, 10%) than disease control patients (16/20, 80%) and healthy children (14/20, 70%). KD patients had no significant incidences of other microbial genera, compared with both disease control and healthy children. CONCLUSION: The results suggest that a lack or loss of the beneficial Lactobacillus genus in the enteric microflora may occur during the acute phase of KD.

Delayed apoptosis of circulating neutrophils in Kawasaki disease.

Circulating polymorphonuclear neutrophils (PMNs) are known to increase in number and are functionally activated in the acute phase of Kawasaki disease (KD). In the present study, we investigated whether the apoptosis of PMNs is deregulated in KD. When the isolated PMNs were cultured in vitro, the proportions of spontaneous apoptotic PMNs (annexin V+ cells and cells with fragmented DNA) were found to be significantly lower (P < 0.01) in the patients with KD (n = 25) than in the patients with a bacterial infection (n = 20) or a viral infection (n = 20), or in healthy children (n = 20). The proportion of circulating Fas-positive PMNs was also significantly lower (P < 0.01) in the acute KD patients than in the other groups. In the acute phase of KD, the proportion of spontaneous apoptotic PMNs showed a significant positive correlation (P < 0.01) with the proportions of circulating Fas-positive PMNs. Furthermore, the agonistic anti-Fas MoAb (CH-11) induced a significant increase in the proportion of apoptotic PMNs in the patients with a viral infection and healthy children, but not in either the patients with KD or the patients with a bacterial infection. In the intracellular expression of anti- and pro-apoptotic proteins, the A1/Bax ratio was significantly higher in acute KD than in the other groups. These findings indicate that PMN apoptosis is inhibited during the acute phase of KD and also suggest that both the resistance against the Fas-mediated death signal and the down-regulation of the mitochondrial apoptotic signalling pathway due to an altered balance of Bcl-2 protein expression are responsible for the delayed PMN apoptosis.

Production of platelet-activating factor by neuronal cells in the rat brain with cold injury.

The production and localization of platelet-activating factor (PAF) in the brain following focal brain injury were examined. Immunofluorescent staining was used to detect PAF in the rat brain with cold-induced local brain injury. After cold injury, immediate-early PAF staining was observed within the cold lesion followed later by immunoreactivity in the ipsilateral white matter. PAF immunoreactivity was also clearly seen both in cortical neurons adjacent to the cold lesion and in the ipsilateral hippocampus which showed delayed neuronal degeneration. The data suggest that PAF synthesis occurs in the neuronal cells in the perilesional area and hippocampus as well as within the cold lesion site during the early stages of cold-induced brain injury. PAF expression may contribute to the onset and progression of further brain damage, such as delayed axotomy and delayed neuronal loss.

Elevated serum levels of matrix metalloproteinase-9 (MMP-9) in Kawasaki disease.

Matrix metalloproteinases (MMPs) play an important role in the progression of tumour cells and the invasion of inflammatory cells by degrading the extracellular matrix. In the MMP family, MMP-9 gelatinase is thought to contribute to the pathogenesis of inflammatory arteritis by disrupting the elastic lamina. The aim of the present study is to investigate the potential role of MMP-9 in Kawasaki disease (KD), an acute type of systemic vasculitis in children. We studied the total levels of MMP-9 (free proMMP-9 and free MMP-9) in the sera using a new assay system and the expression of MMP-9 mRNA in the leucocytes using reverse transcription-polymerase chain reaction in 18 patients with KD, 10 patients with sepsis and 10 healthy children (HC). The serum MMP-9 levels were significantly higher (P < 0.01) in the acute phase of KD than in the acute phase of sepsis and HC. In the time course of KD, the serum MMP-9 levels decreased significantly (P < 0.01) from the subacute through the convalescent phases. In the acute phase of KD, the serum MMP-9 levels showed a significantly positive correlation (P < 0.05) with the circulating leucocyte counts, especially the neutrophil counts. Furthermore, the expression of MMP-9 mRNA in the circulating leucocytes increased in the acute phase of KD and decreased from the subacute through the convalescent phases. These findings indicate that an excessive amount of MMP-9 is present in the plasma during the acute phase of KD, thus suggesting that circulating leucocytes may be a source of the MMP-9 secreted into the circulation.

Cervical myelopathy due to compression by bilateral vertebral arteries--case report.

A 69-year-old man presented with progressive cervical myelopathy due to vascular compression of the upper cervical spinal cord. Vertebral angiography and magnetic resonance imaging revealed that the elongated bilateral vertebral arteries (VAs) had compressed the spinal cord at the C-2 level. The spinal cord was surgically decompressed laterally by retracting the VAs with Gore-Tex tape and anchoring them to the dura. The patient's symptoms improved postoperatively. Decompression and anchoring of the causative vessels is recommended due to the large size of the VAs.

Formation of stable foam by the cells and culture supernatant of Gordonia (Nocardia) amarae.

Gordonia amarae is the cause of foaming activated sludge. In this study, the mechanism of foam formation by G. amarae SC1 was investigated. A liquid culture of SC1 cells generated a stable foam when shaken reciprocally. This foam formation was dependent on the presence of both bacterial cells and culture supernatant. A high-molecular-weight fraction (Mw>10000) of the supernatant was capable of emulsifying n-hexadecane in addition to exhibiting foaming activity, indicating that it contains a surface-active substance(s). The bacterial cells showed a high affinity to hexadecane. This hydrophobic cell surface property might be involved in the attachment of cells to air bubbles to generate a stable foam. The results demonstrated the participation of cells and the extracellular biosurfactant in the formation and stabilization of foam in G. amarae SC1 culture.

Neurochemical monitoring in the management of severe head-injured patients with hypothermia.

The neuroprotective action and effect of hypothermia on the neurochemical system is not well understood. The present study was performed using six patients with GCS scores of 5 or less to clarify the relationship between monitored brain temperature, intracranial pressure (ICP), cerebral perfusion pressure (CPP) and oxygen saturation of the jugular venous blood (SjO2). Changes in concentration of excitatory amino acids, glutamate (GLU) and aspartate (ASP), and NO2 were studied using intracerebral microdialysis as well as in jugular venous blood and cerebrospinal fluid (CSF). Changes in brain temperature, CPP and SjO2 resulting from hypothermia and brain death associated with markedly higher concentrations of and fluctuations in the concentrations of GLU, ASP and NO2 were observed in the dialysate than in the jugular venous blood or CSF. Hypothermic treatment significantly reduces excitatory amino acid and NO2 concentrations, a finding which was associated with an improvement in CPP and SjO2. Measurement of GLU and ASP using intracerebral microdialysis is a clinically useful method for clarifying abnormal neurochemical events associated with severe head injury and for evaluating the effects of hypothermia.

Delayed CSF pseudocyst following shunt malfunction after myelomeningocele repair.

We report a case of delayed cerebrospinal fluid (CSF) pseudocyst following shunt malfunction in a 20-year-old patient with myelomeningocele. Magnetic resonance (MR) images and a radioimmunoassay shunt-gram detected the CSF fistula at the old scar of the myelomeningocele repaired 20 years before. Since the revision of the shunt system failed to keep the pseudocyst, the lesion was successfully directly repaired. Treatment of the delayed CSF pseudocyst following shunt malfunction thus requires a radical operation of the lesion.

Intraventricular malignant triton tumour.

The authors present the clinical and pathological features of a malignant triton tumour (MTT) in the lateral ventricle with neurofibromatosis type 1. A 57 year-old man presented with disorientation and memory disturbance. A Computed tomographic scan and magnetic resonance imaging studies revealed an enhancing lesion in the left lateral ventricle. A parieto-occipital transcallosal approach was taken and resection of the lesion was performed. The operative findings suggested that the tumour arose from the perivascular nerves. The final pathological diagnosis was a MTT. This is the first case of an intraventricular MTT. Aggressive treatment including radical surgery combined with radiochemotherapy is recommended for a MTT of the central nervous system.

Efficacy of temporal musculopericranial flap for reconstruction of the anterior base of the skull.

Since March 1988 the temporal musculopericranial (TMP) flap has been used as our flap of choice to reconstruct defects of the anterior base of the skull that are larger than 2 x 3 cm, including the dura mater, in 33 patients. The primary diseases were malignant head and neck tumours (n = 16), trauma (n = 15), meningioma (n = 1), and teratoma (n = 1). The dura mater was reconstructed with a unilateral TMP flap, after which the cranial and nasal cavities were closed with the opposite TMP flap. In addition, bone was grafted by sandwiching the bone between the two flaps and fixing it to the surrounding residual bone. When a large area was resected, making it impossible to use a TMP flap, a frontal musculopericranial (FMP) flap or a free flap (usually the rectus abdominis myocutaneous flap) was used to close the cranial and nasal cavities. Thirty of the 33 patients recovered with no postoperative complications. Two patients developed extradural abscesses in the anterior base of the skull and one developed mild meningitis, but they were successfully treated conservatively. When bilateral TMP flaps were used for the reconstruction, no patient had aesthetic problems in the forehead region. The TMP flap is extremely effective for the reconstruction of the anterior base of the skull because it is minimally invasive and causes few aesthetic problems in the forehead region.

High-grade adenoid cystic carcinoma originating from the lacrimal gland.

Among primary lacrimal gland tumors, adenoid cystic carcinoma (ACC) is the most common malignant epithelial neoplasm; it is characterized by local intracranial invasion. A case with unusual dumbbell-type intracranial extension representing cavernous sinus syndrome is described. A 49-year-old woman was admitted to our hospital with right cavernous sinus syndrome. Computerized tomographic (CT) scans and magnetic resonance (MR) imaging demonstrated well-enhanced intraorbital and middle fossa tumors mimicking multifocal mass lesions. Operative findings revealed an ACC originating from the lacrimal gland and extending into the right cavernous sinus and middle fossa along the nerve sheath in the superior orbital fissure. Although MR image findings of intracranial ACC often resemble the image findings for meningiomas, intracranial ACC is very aggressive in comparison with meningioma. It is best treated surgically and aggressively.

Syringobulbia caused by delayed postoperative tethering of the cervical spinal cord - delayed complication of foramen magnum decompression for Chiari malformation.

Postoperative tethering of the high cervical spinal cord is a rare cause of neurological deterioration after foramen magnum decompression (FMD) with duraplasty for Chiari type I malformation. A review of the literature revealed that only 5 cases have been reported. This entity is not widely known to occur as a complication of the common surgical procedure for Chiari type I malformation. A 17-year-old boy experienced rapidly progressive neurological deterioration over a 3-month period. FMD and duraplasty with lyophilized cadaver dura had been performed 8 years previously. Follow-up MR images showed that the cerebrospinal fluid (CSF) space dorsal to the cord was gradually disappearing and that syringobulbia had developed. Opening the dura mater of the posterior fossa revealed dense fibrous scarring, arachnoid thickening over the cervicomedullary area, and tethering the cord to the dura from the medulla to C2. The adhesions were dissected free, and the tethering was released. A syringosubarachnoid (SS) shunt was inserted and duraplasty was performed with an expended polytetrafluoroethylene sheet (Gore-Tex). Postoperative MR images demonstrated that the syringobulbia had completely collapsed and that a dorsal CSF space was present. Follow-up MR images provided significant information on the cervical spinal cord tethering after FMD with duraplasty for Chiari malformation. We encourage sharp surgical detethering and duraplasty with Gore-Tex to avoid retethering. Early recognition and treatment of this unusual but important complication are emphasized.